Patent GB-1527374-A (GB)
Title: Electric rotating machine
IPC: H02K23/26
Filed: 1975-09-08
Abstract: 1527374 Rotary machines PORTESCAP 8 Sept 1975 [6 Sept 1974 11 July 1975] 36909/75 Heading H2A An electric rotating machine has a rotor with a cylindrical self-supporting oblique main winding, the winding comprising a plurality of sections (1-2), (2-3) &c., Fig. 1A, all connected in series with one another with the opposite ends of each section being connected to adjacent sections of a commutator C on the rotor, each said section being formed of at least two series-connected coil elements, such as 1b 2b for section (1-2), which elements are staggered relative to one another in the peripheral direction around the rotor axis, each said coil element being represented by two oblique conductor portions which intersect at an angle, Fig. 2A (not shown), and the winding sections are arranged on the rotor so that at least one of the coil elements of one section and at least one of the coil elements of a different section, e.g. elements 2b, 26<SP>1</SP> of sections (1-2), (2-3), are disposed so as to be located concurrently in the commutation zone during rotor rotation so that currents flow through said respective coil elements, 2b, 26<SP>1</SP> of said different sections in opposite directions. The arrangement reduces the effects of voltage peaks induced by commutation. A D.C. motor may have a two layer rotor winding B formed by coil elements 1b to 9b and 1b<SP>1</SP> to 9b<SP>1</SP>. The segments 1 to 9 of commutator C are connected to points 1 to 9 respectively on the winding so that winding section (1-2) is formed by elements 1b and 2b, section (2-3) by elements 2b<SP>1</SP> and 3b<SP>1</SP> &c., any two superimposed elements, e.g. 2b, 26<SP>1</SP>, being in different sections. The arrows in Fig. 1A show the current directions when commutator segments 2, 6, 7 are contacted by brushes, currents in sections (1-2) and (2-3) then being in opposite directions. An alternative form has the superposed coils, such as 2b, 2b<SP>1</SP>, in Fig. 1A arranged side-by-side in the general axial direction of the rotor at the same distance from the axis. In a three layer winding, Fig. 3 (not shown), each section is formed by three peripherally spaced coil elements in the same layer with the various sections partially overlapping. In a four layer winding, Fig. 4 (not shown), each section has four coil elements in two peripherally spaced pairs, the two coil elements in each pair being superposed, one pair of each section being interleaved in superposed relation with a pair of coil elements of an adjacent section and the other pair being interleaved in superposed relation with a pair of a different adjacent section. A motor-generator, Fig. 5, has a rotor with a motor winding 12 with sections connected at their ends to points I to IX connected to corresponding segments of motor commutator 14, and a generator winding 13 similarly connected to commutator 15. Radial planes of symmetry of each motor winding section are at an angle α to such planes of corresponding generator winding sections, α being #/N 5 , where N 5  is the number of sections (9 as shown) in each winding. Motor commutator 14 is cylindrical and generator commutator 15 discshaped.